We are thinking of transferring more than $10k into our us bank account. Who do we have to tell?

No-one.

Nobody.

The bank will report it for you - if they see a reason to...

Do we not have to declare it for tax purposes?

Only the interest you earn from it - it will all go in the appropriate boxes on your tax return.

If it was yours to start with, you're not earning it, it's just cash you're just moving it from one pocket to the other. Right?

Ah, but then it starts getting complicated as you're not just factoring the monetary exchange rate but also the conversion between UK and US clothing sizes.

We thought we were onto a winner when we decided to keep it under the mattress, but thanks to the market volatility between the UK double and the US queen we ended up losing more than just a few nights' sleep I can tell you...

The reporting requirements are for CASH transactions (or cashiers checks) but electronic transfers do not (on their own) trigger the reporting requirements.

As for 'tax'--whether you owe tax or don't depends on the money. If it is your savings, then you have probably already paid tax on it before you put it in the bank. No need to pay another simply because you are transferring it to another bank. If the money is coming from a 3rd party (i.e. not been taxed, aka income to you) then there will be tax issues regardless of whether it is in the bank here or there, but those will arise as part of the normal tax filing.

I understand it as applying to *any* 'monetary instrument' according to cbp.gov

And, that if you make the xfer electronically (wire transfer), the bank simply does any required reporting. That's how it went for us.

The bank will only report it if it looks suspicious to them.

The bank MUST report any single transfer of $10K whether over wire or you walk in with cash. Neither party (sender/receiver) has to report anything. However, if there are significant transfers that don't square up with one's tax filings, or the amount/# of transfers is big, then you might get investigated by a federal tax agency or if they think you are a terrorist, DHS/FBI.

Used to be mainly to try and prevent tax fraud, now it's also supposed to prevent terrorists from transferring large sums of money. I guess they send $9999.99.

This applies only cash or equivalent transaction, or ANY transaction - of whatever size - that is deemed suspicious.

It does not affect a transfer from a foreign account to a US account - unless the transaction is deemed to be suspicious.

I'll rephrase. In the banks where my father worked, a wire transfer of $10k would be highly unusual in itself and would be reported every single time. Hell, anyone with $10k spare would be positively wealthy there!

I suppose a big bank in a big city with customers with big accounts probably would not report something if it were common for that person.

I think there are two reporting requirements, one for individuals and one for banks.

For an individual, it's a monetary instrument or negotiable instrument or some term that includes CASH and cashiers checks, but not wire transfers. For banks, they are to watch for basically 'anything' that looks suspicious and report it, or something like that.

Not according to my bank ..all transactions of over $10k are reported ..
especially coming from abroad ...